Subsurface well packers



Nov. 1, 1966 J. R- CLAYCOMB SUBSURFACE WELL PACKERS Filed March 9, 1964 2 Sheets-Sheet l i --4o 4 k 2 I4 INVENTOR JQCKSON R. CLQVCOMB BY WMW ATTORNEVS 1966 J. R. CLAYCOMB 3, 8 ,346

SUBSURFACE WELL PACKERS Filed March 9, 1964 2 Sheets-Sheet 2 ISQ JACKSON 12. CLm/co/ws INVENTOR.

MUM M ATTOQNEVS United States Patent "ice 3,282,346 SUBSURFACE WELL PACKERS Jackson R. Claycomb, Tempe, Ariz., assignor to Baker Oil Tools, Inc., Los Angeles, Calif, a corporation of California Filed Mar. 9, 1964, Ser. No. 350,206 18 Claims. (Cl. 166-182) The present invention relates to subsurface well tools, and more particularly to well packers, including bridge plugs, adapted to be set in well casings and similar well conduits disposed in well bores.

Well packers of different specific types, such as bridge plugs, squeeze packers and production packers, have been set in casing strings disposed in well bores for the purpose of providing seals and anchors in the casing capable of preventing fluid flow around the packers and of resisting fluid pressures tending to move the set packers in the casing. Usually, rubber or rubber-like materials have been used as the packing element or sealing structure. Expandable slips have been used for anchoring the packer against the casing. In some cases, lead has been proposed for at least a portion of the packing structure.

Prior well packers embodying rubber or lead as packing materials have failed under high temperature operating conditions, as, for example, when subjected to high pressure steam, which might elevate the packer temperature from about 550 F. to about 750 F. Failure is accented when the packer is subjected to thermal cycling, that is, to alternate heating and cooling. A primary cause of failure is extrusion of the packing material, particularly at elevated temperatures, such extrusion being accelerated upon subjecting the packer to combinations of high temperature and high pressure. Attempts at minimizing packing extrusion results in relatively complex and costly well packers, which still have a high incidence of failures.

Accordingly, an object of the present invention is to provide a comparatively simple and economical well packer capable of being set in packed-01f condition in a Well conduit and of withstanding comparatively high temperatures without leaking.

Another object of the invention is to provide a well packer capable of being anchored in packed-off condition against the wall of a well conduit without the use of slips. The packing element both seals and anchors against the conduit wall to withstand comparatively high temperature and pressure operating conditions, the packing element undergoing no deleterious extrusion when subjected to high temperatures while tenaciously frictionally gripping the conduit wall.

A further object of the invention is to provide a well packer adapted to be set in packed-01f condition in a well conduit and of safely withstanding relatively high pressures and thermal cycling, involving alternate heating and cooling, over relatively wide temperature ranges imposed on the packer when set within the well conduit.

An additional object of the invention is to provide a well packer having a ductile and malleable packing element adapted to be expanded against the wall of the well conduit with a relatively low setting force, and yet be capable of safely withstanding high temperature and pressure operating conditions. The ductile and malleable element also functions to frictionally grip the wall of Patented Nov. 1, 1966 the well conduit to anchor the well packer against movement therewithin.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several forms in which'it may be embodied. Such forms are shown in the drawings accompanying and forming part of the present specification. These forms ,will now be described in detail for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims. 1

Referring to the drawings:

FIGURE 1 is a combined side elevation and longitudinal sectional View .of an embodiment of the invention disposed in a well conduit, with the parts in their initial position for -lowering the apparatus through the well conduit;

FIG. 2 is a view similar to FIG. 1 of the lower portion of the apparatus set against the wall of the well conduit;

FIG. 3 is a view similar to FIG. 2 of the setting tool released from the set well packer and removed from the well conduit;

FIG. 4 is a cross-section taken along the line 44 on FIG. 3;

FIG. 5 is a combined longitudinal section and side elevational view of"; modified form of well packer apparatus, with the parts' in their initial condition for lowering the apparatus in a well conduit;

FIG. 6 is a view of the lower packer portion of the apparatus set in the well conduit;

FIG. 7 is an enlarged fragmentary longitudinal section of the lock portion of the packer apparatus disclosed in FIG. 6.

As shown in FIGS. 1 to 4, inclusive, a well packer A, in the form of a bridge plug, is adapted to be anchored in packed-off condition in a string of well casing B, or similar conduit string, disposed in a well bore, the well casing extending to the top of the latter. The bridge plug or packer apparatus is lowered in the well casing on a suitable running-in string (not shown), such as a wire line connected to a setting tool C that includes an inner mandrel 10 and an outer thrust sleeve 11. The setting tool can be of the type disclosed and described in United States Patent No. 2,637,402, in which a propellant or power charge (not shown) burns away to develop a gas at an increasing pressure for exerting an upward tension or pull on the mandrel 10 and a downward thrust on the sleeve 11. It is the combination of the upward pull on the mandrel and the downward thrust on the sleeve which is availed of for anchoring the plug A in leakproof relation in the well casing.

As disclosed, the bridge plug or packer includes a central body 12, which may be made of a suitable material, such as cast iron, that has a lower flange or shoulder 13, the upper surface 14 of which may, if desired, be inclined in a downward and outward direction so as to function as an expander. Since the well packer specifically disclosed is intended to function as a barrier or bridge plug across the full internal diameter of the well casing, the

body of the :tool has a transverse partition 15 to fully close wardly over the periphery 18 of the body and into firm frictional and sealing engagement with the wall of the well casing B. As disclosed, the packing and anchoring element 17 is in the form of a sleeve, having a cylindrical inner wall 19 of a substantially lesser diameter than the outside diameter 13 of the body of the tool. The exterior 20 of the packing element or sleeve is also cylindrical, having an initial diameter substantially less than the inside diameter of the casing B, to permit its ready lowering through the well casing.

The sleeve 17 is mounted upon another body member in the form of a tens-ion mandrel 21, which actually forms part of the setting tool for the bridge plug, the lower portion 22 of the tension mandrel being of reduced diameter and piloted within the upper passage 16 of the hollow body 12. The lower pilot portion 22 of the mandrel is initially releasably secured to the body by a shear ring 23, which may be made in two pieces, and received within a peripheral groove 24 in the pilot portion of the mandrel. The outer portion of the shear ring extends into an internal groove 25 formed in the body and provided between an upwardly facing shoulder 26 of the body and a ring 27 threaded into the body to clamp or hold the two-piece or split shear ring against the shoulder.

The mandrel 21 has a transverse downwardly facing shoulder 28 at the upper end of its pilot portion engaging the upper end of the packer or bridge plug body 12. This shoulder may extend outwardly to the periphery 29 of the upper portion of the body, from which it has a tapered expander or f-rusto-conical portion 30 inclined in an upward and inward direction and merging into an elongate cylindrical portion 31 of the tension mandrel, surrounded initially by the packing and anchoring element 17. Initially, as disclosed in FIG. 1, the lower end of the packing element 17 is disposed immediately above the smaller diameter of the frusto-conical expander portion 30 of the mandrel. The upper end of the tension mandrel 21 is threadedly secured to the lower end of the setting tool mandrel 10, there being a setting sleeve 32 surrounding the mandrel 21 and threadedly secured to the lower end of the thrust sleeve 11, the lower end of the setting sleeve engaging the upper end of the packing and anchoring element 17.

The packing element 17 is made of a ductile and malleable material, such as substantially pure or other soft aluminum, a soft brass, or copper. The material of the element is such that it can be shifted downwardly and stretched over the tapered expander 30 to increase its internal and external diameters without rupturing. Upon being stretched or expanded outwardly, the wall thickness of the element or sleeve 17 may actually decrease, its increased external diameter, however, conforming closely to the inside diameter of the casing wall. Upon being brought outwardly into engagement with the casing wall, with the body 12 of the tool disposed substantially completely within the packing element or sleeve 17, the latter can be then shortened slightly or compressed to insure its firm frictional engagement with the wall of the well casing, and also with the periphery 18 of the packer body. To enhance the unit force of engagement of the packing element 17 with the wall of the well casing B, its exterior portion may be formed as a plurality of longitudinally spaced circumferential ribs 34.

The apparatus illustrated in FIG. 1 is secured to the setting tool C and the wire line (not shown), and lowered in the casing B to the location at which the well packer is to be set., The setting tool is then actuated, as in the manner described in United States Patent No. 2,637,402, to develop a substantial force which acts upwardly on the mandrel and downwardly on the thrust sleeve 11, the mandrel 10 moving upwardly and the thrust sleeve 11 relatively downwardly, to move the mandrel 21 relatively upwardly within the ductile and malleable packing element 17 and expand the latter outwardly toward and against the wall of 'the well casing, followed by pulling of the body portion 12 of the packer upwardly within the expanded packing element until it is disposed substantially entirely within the packing element, such as shown in FIG. 2. To facilitate the relative longitudinal movement of the packing element 17 along the mandrel 21 and packer body 12, the element may have a plurality of longitudinally spaced, shallow circumferential grooves 35 in which a suitable lubricant is placed. The presence of such lubricant facilitates the relative downward sliding of the packing element 17 along the mandrel 21, over its expander 30, and over the packer body 12.

The packing element 17 is shifted downwardly by the downward force imposed upon it through the thrust sleeve 11 and setting sleeve 32 until its lower end engages the lower body shoulder or expander 13, which will further stretch or urge the packing element outwardly into firm engagement with the wall of the well casing. The thrust sleeve 11 and settting sleeve 32 continue to exert a downward force on the packing element 17 and the mandrel 10 and tension mandrel 21 continue to exert an upward force on the body 12 and the packing element 17 to firmly press the ribs 34 of the packing sleeve into leakproof and frictional engagement against the wall of the well casing B and also firmly against the periphery 18 ofv the body (FIG. 2). The force in the setting tool C continues to increase to further increase the setting force on the packing sleeve imposed by the setting sleeve 32, the mandrel 21 and the body 12, until the shear strength of the ring 23 is exceeded, the latter being disrupted and effecting a disconnection of the mandrel 21 from the body of the tool. The setting tool C and mandrel 21 are thereby released from the body 12, allowing the setting tool to be elevated in the Well casing B, or other conduit string in the well bore, and removed entirely therefrom at the top of the hole, leaving the bridge plug A set in the well casing (FIG. 3). Any tendency of the packing element 17 to return upwardly along the body 12 of the plug or packer is prevented by a split lock ring 40 disposed in a peripheral groove 41 in the body, this ring having a bevelled upper surface 42 inclined in a downward and outward direction, to facilitate downward sliding of the packing sleeve 17 thereover, the ring digging into the upper, inner portion of the packing sleeve to preclude its upward movement along the body 12.

The setting force imposed by the setting tool on the packing element 17 to shift it over the expander 30 and body 12 and obtain a firm leakproof seal and frictional engagement against the wall of the casing B, and also against the periphery of the body 12, can be substantial. As an example, assumim the well casing to have an outside diameter of 5 /2 inches, the shear ring 23 may be selected as to be sheared or disrupted at from about 35,000 lbs. to 80,000 lbs. to secure stretching of the packing and anchoring element 17 over the expander portion 30 of the mandrel 21 and relatively downwardly along the body 12, and to compress it firmly against the wall of the casing and the exterior of the body, with assurance that the force of frictional engagement of the packing element 17 against the wall of the well casing B will be such as to anchor the bridge plug A to the casing and render it capable of withstanding comparatively high pressure dififerentials of the order of 4,000 to 5,000 psi.

Actual operations of the bridge plug disclosed and its setting in 5 /2 O.D. well casing has demonstrated the ability of the set packer to withstand high fluid pressures and high temperatures in the well casing without leaking and without movement.

Tests have shown that the plug remains anchored and sealed off in the well casing despite being subjected to widely varying temperature changes. As an example, the bridge plug A was set in the well casing when cold and temperatures as high as about 700 F. imposed upon it. The application of fluid pressure to the interior of the casing, while the elevated temperature was maintained,

demonstrated the ability of the set bridge plug to remain anchored in leakproof condition within the casing. Upon reducing the temperature in the well casing and reapplying pressures of the order of 3,000 to 4,000 p.s.i., the bridge plug remained set in packed-off condition in the well casing without leaking. The packer held when the fluid in the well casing at the location of the packer was alternately subjected to heat and cold, andthe fluid pressure maintained thereon. Extrusion of the aluminum material of the packing sleeve 17 between the body 12 and the well casing did not occur.

The packing element or sleeve must be of material having appropriate physical characteristics to withstand high temperatures, repeated cycling of temperatures between relatively cold temperatures, which, for example, might be less than 100 F., and elevated temperatures as high as about 800 F., all without extruding between the body 12 of the tool and the wall casing B. As an example, substantially pure aluminum, from which packing and anchoring elements 17 have been made, as a melting point of about 1,220 E, or well above the maximum temperature to which the bridge plug would be subjected in a well bore. Such substantially pure aluminum would also have a yield point of between about 5,000 to l5,000 p.s.i., so that it is, in effect, stressed beyond its yield point in being expanded along the tapered expander 30 and over the body 12 of the tool, and compressed firmly between the wall of the well casing B and the exterior 18 of the body member.

Since the aluminum packing element 17 has a much greater coefficient of expansion than the cast-iron body portion 12 of the packer and of the steel casing B, the setting of the bridge plug in the well casing in a cold state will result in the aluminum expanding to a greater extent than the body of the packer and the well casing when the temperature of the liquid, or other fluid, in the well casing is elevated to a considerable degree, as, for example, upon subjecting the plug to the action of high pressure steam. Accordingly, the aluminum packing sleeve 17 will grip both the body 12 of the packer and the wall of the well casing B more tenaciously as its temperature increases, not only increasing the resistance to leaking of the packing sleeve with respect to the casing and body, but also greatly increasing its gripping force against the wall of the well casing.

The external ribs 34 on the packing sleeve 17 enable the packing element to be stretched or expanded outwardly and sealed and anchored firmly against the wall of the well casing and against the periphery 18 of the body with a much lesser longitudinal force imposed on the sleeve 17 through the tension mandrel 21 and the thrust setting sleeve 32 than would be the case in the absence of the rib feature, in which the periphery 20 of the sleeve would be cylindrical and smooth. Not only is the sleeve 17 capable of being set against the well casing with a lesser setting force, but the ribs 34 themselves are compressed against the casing with a higher unit pressure, resulting in their holding against the wall of the well casing more effectively.

In the form of invention illustrated in FIGS. 5 to 7, another specific well packer or bridge plug is disclosed in which the body 12a of the tool has a lower shoulder or flange 13a below a cylindrical body portion 18a, the upper end of such cylindrical portion merging into an expander or frusto-conical portion 30a that tapers upwardly and inwardly, the upper end of the expander portion, in turn, merging into another cylindrical portion 60 of lesser diameter than the lower cylindrical portion 18a of the body, and having downwardly facing circular ratchet teeth 61 extending longitudinally thereof. The body has a partition 15a across and closing its hollow bore 16a, and is threadedly secured to a tension rod or stud 23a having a reduced diameter or weakened portion 62 at which the rod or stud can pull apart. The upper end of the tension stud is threadedly attached to a cylindrical tension mandrel 21a, the upper end of which is threadly secured to a mandrel 10 forming part of a setting tool or apparatus C which can be of substantially the same type as disclosed in United States Patent No. 2,637,402. This setting too-1 includes a thrust sleeve 11, as in the other form of the invention, threadedly attached to another thrust or setting sleeve 32a surrounding the tension mandrel 21a.

An elongate packing element or sleeve 17a may initially surround the tension mandrel 2111, which may have substantially the same external diameter as the ratchet portion 60 of the body 12a of the tool, which is substantially less than the lower external diameter 18a of the packer body. The upper end of the elongate packing and anchoring element 17a is threadedly secured to a setting ring 65, the upper end of which is engaged by the lower end of the thrust sleeve 32a. This setting ring contains a split lock ring 66 having internal ratchet teeth 67 facing in an upward direction and adapted to coact with the body ratchet teeth 61. The split lock ring also has external tapered cam teeth 68 adapted to engage companion internal cam teeth 69 in the setting ring 65, the cam teeth being inclined in an upward and outward direction. In the event that the setting ring 65 tends to move upwardly relative to the lock ring 66, the cam teeth 68, 69 coengage and urge the lock ring inwardly.

The packing element 17a has a cylindrical exterior 20a of a substantially lesser initial diameter than the inside diameter of the well casing B. Such cylindrical exterior may be of an interrupted type, being provided by spaced circumferential ribs 34a of the same character as on the packing element in the other form of the invention. The packing and anchoring element 17a may also be made of a soft ductile malleable material, such as soft aluminum, a soft brass, or copper, and, in fact, may be made of a soft iron, such as wrought iron. The material is such that it is capable of being stretched and expanded outwardly upon being moved relatively downwardly along the expander 30a to increase its internal diameter, which may, perhaps, decrease the overall radial thickness of the sleeve 17a to the extent at which the sleeve can pass between the periphery of the enlarged diameter portion 18a of the body 12a and the casing wall, to be forced against such wall of the well casing and also against the periphery of the body portion of greater diameter.

As shown in FIG. 5, the apparatus is lowered in the well casing on a wire line (not shown) and setting tool C, until the location in the casing is reached at which the bridge plug is to be anchored in packed-off condition. When such point is reached, the setting tool is actuated to generate gas at an increasing pressure therewithin, which will result in an upward pull and movement on the mandrel 10 and tension mandrel 21a, and through the tension stud 23a 0n the body 12a of the well packer. Such generated pressure also results in a downward movement and thust of the setting sleeves 11, 32a upon the setting ring 65 and the upper end of the packing element 17a. Such relative movements effect relative upward shifting of the tension mandrel 21a and body 12a of the tool within the packing element 17a, or in a relative downward movement of the packing element along the tension mandrel and body of the tool, causing the expander 30a to stretch and enlarge the internal diameter of the packing and anchoring element 17a, the latter being shifted relatively downwardly along the expander and onto the larger diameter cylindrical portion 18a of the body, until it engages the body shoulder 13a, which serves as an abutment preventing further downward movement of the lower end of the packing element. At this time, the ratchet ring 65 is disposed opposite the ratchet teeth 61 on the body, and any further downward force imposed by the thrust sleeve 32a through the setting ring 65 on the upper end of the packing element 17a will compress the latter and force its ribs 34a against the wall of the well casing B and its inner surface against the periphery of the enlarged portion 18a of the body. The

ratchet ring teeth 67 engage the body teeth 61 and prevent the setting ring 66 from moving upwardly, thereby preventing any elasticity in the sleeve 17a of aluminum, or other suitable material, from allowing the sleeve to elongate and perhaps release or reduce its friction grip on the wall of the well casing and against the periphery 18a of the body (FIG. 6).

When the setting force imposed through the thrust sleeve 32a on the upper end of the packing element 17a, and through the mandrel 21a, tension stud 23a and body 12a on the shoulder 13a and upon the lower end of the packing element, exceeds the strength of the weakened portion 62 of the tension stud, the latter is disrupted or pulled apart at such weakened portion, effecting disconnection of the setting tool C from the plug, the upper portion of the tension stud 23a, the tension mandrel 21a and the thrust sleeve 32a being elevated in the casing on the wire line and setting tool, and removed from the well casing B, leaving the plug anchored in the well casing.

In general, the bridge plug disclosed in FIGS. to 7 is anchored in packed-off condition in the well casing in much the same manner as the apparatus disclosed in FIGS. 1 to 4. In lieu of the expander 30 being placed on the mandrel 21, it is placed on the body 12a of the tool. As in the other form of the invention, the interior of the soft aluminum packing element 17a may have longitudinally spaced, circumferential internal grooves 35a therein for reception of a suitable lubricant to facilitate downward sliding of the sleeve along the mandrel 21a and body 12a of the tool to its final set position tenaciously frictionally gripping the body of the tool and the wall of the well casing.

The two specific well packers or bridge plugs disclosed are relatively economical to manufacture, since they are comparatively simple in construction. The aluminum or similar sleeve 12, 12a serves both the purpose of the packing element and slips or other anchoring elements in prior well packer devices. The material of the packing element 17, 17a is such that it is ductile and malleable, having a comparatively high melting point, allowing it to remain anchored in packed-off condition against the well casing despite being subjected to elevated temperatures and alternately to both relatively low and relatively high temperatures. The material of which the sleeve is made is such that its yield point is exceeded in being expanded over the body of the tool and against the wall of the well casing, such that the packing element 17, 17a tends to remain in its set position. Despite the yield point having been exceeded, the ultimate strength of the material is not exceeded, the sleeve being in a compressed state, exerting a high degree of friction force against the wall of the well casing and also against the periphery of the body.

I claim:

1. In a well packer adapted to be set in a conduit disposed in a well bore: body means; initially retracted annular packing means of a ductile malleable material having a melting point above about 800 F. and adapted to surround said body means; expander means movable relatively longitudinally within said packing means to enlarge its internal and external diameters and force it against the conduit; and means for shifting said packing means and expander means simultaneously in opposite longitudinal directions to enlarge said packing means.

2. In a well packer adapted to be set in a conduit disposed in a well bore: body means; initially retracted annular packing means of a ductile malleable material having a melting point above about 800 F. and adapted to surround said body means; expander means movable relatively longitudinally within said packing means to enlarge its internal and external diameters and force it against the conduit; said packing means having a plurality of longitudinally spaced external circumferential ribs; and means for shifting said packing means and expander means simultaneously in opposite longitudinal directions to enlarge said packing means.

3. In a well packer adapted to be set in a conduit disposed in a well bore: body means; initially retracted annular packing means of a ductile malleable material having a melting point above about 800 F. and adapted to surround said body means; and expander means movable relatively longitudinally within said packing means to enlarge its internal and external diameters and force it against the conduit; said packing means having one or more internal circumferential grooves adapted to contain a lubricant.

4. In a well packer adapted to be set in a conduit disposed in a well bore: body means; initially retracted annular packing means of a ductile malleable material having a melting point above about 800 F, and adapted to surround said body means; and expander means movable relatively longitudinally within said packing means to enlarge its internal and external diameters and force it against the conduit; said packing means having a plurality of longitudinally spaced external circumferential ribs and one or more internal circumferential grooves adapted to contain a lubricant.

5. In a well packer adapted to be set in a conduit disposed in a well bore: a body means having a first generally cylindrical peripheral portion and a second generally cylindrical peripheral portion of substantially greater diameter than said first portion and also having a tapered expander between said portions; initially retracted annular packing means of a ductile malleable material having a melting temperature above about 800 F. initially surrounding said first peripheral portion and having an initial internal diameter substantially less than said second portion; and means for relatively shifting said packing means longitudinally along said first portion over said expander onto said second portion and into firm sealing engagement with the conduit and second body portion, the major portion of said packing means being shifted onto said second portion.

6. In a well packer adapted to be set in a conduit disposed in a well bore: body means having a first generally cylindrical peripheral portion and a second generally cylindrical peripheral portion of substantially greater diameter than said first portion and also having a tapered expander between said portions; initially retracted annular packing means of a ductile malleable material having a melting temperature above about 800 F. initially surrounding said first peripheral portion and having an initial internal diameter substantially less than said second portion; and means for relatively shifting said packing means longitudinally along said first portion over said expander onto said second portion and into firm sealing engagement with the conduit and second body portion, the major portion of said packing means being shifted onto said second portion; said packing means having a plurality of longitudinally spaced external circumferential ribs.

7. In a well packer adapted to be set in a conduit disposed in a well bore: body means having a first generally cylindrical peripheral portion and a second generally cylindrical peripheral portion of substantially greater diameter than said first portion and also having a tapered expander between said portions; initially retracted annular packing means of a ductile malleable material having a melting temperature above about 800 F. initially surrounding said first peripheral portion and having an initial internal diameter substantially less than said second portion; and means for relatively shifting said packing means longitudinally along said first portion over said expander onto said second portion and into firm sealing engagement with the conduit and second body portion; said packing means having a plurality of longitudinally spaced external circumferential ribs and one or more internal circumferential grooves adapted to contain a lubricant.

8. In a well packer adapted to be set in a conduit disposed in a well bore: a body member; a mandrel member; means releasably securing said mandrel member to said body member; said body member having a first generally cylindrical peripheral portion; one of said members having a second generally cylindrical peripheral portion of substantially lesser diameter than said first portion; one of said members having a tapered expander between said portions; initially retracted annular packing means of a ductile malleable material having a melting temperature above about 800 F. initially surrounding said second peripheral portion and having an initial internal diameter substantially less than said first portion; and means for relatively shifting said packing means longitudinally along said second portion over said expander onto said first portion and into firm sealing engagement with the conduit and first body portion.

9. In a Well packer adapted to be set in a conduit disposed in a well bore: body means; initially retracted annular packing means of a ductile malleable material having a melting point above about 800 F. and adapted to surround said body means; expander means movable relatively longitudinally within said packing means to enlarge its internal and external diameters and force it against the conduit; and means for compressing said enlarged packing means against the conduit with a force exceeding the yield strength of the packing means material, which force is less than the ultimate strength of said material.

10. In a well packer adapted to be set in a conduit disposed in a well bore: body means having a first generally cylindrical peripheral portion and a second generally cylindrical peripheral portion of substantially greater diameter than said first portion and also having a tapered expander between said portions; initially retracted annular packing means of a ductile malleable material having a melting temperature above about 800 F. initially surrounding said first peripheral portion and having an initial internal diameter substantially less than said second portion; means for relatively shifting said packing means longitudinally along said first portion over said expander onto said second portion and into firm sealing engagement with the conduit and second body portion; said shifting means being adapted to compress said packing means against the conduit with a force exceeding the yield strength of the packing means material, which force is less than the ultimate strength of said material.

11. In a well packer adapted to be set in a conduit disposed in a well bore: a body; a mandrel; means releasably securing said mandrel to said body; said body having a first generally cylindrical peripheral portion; said mandrel having a second generally cylindrical Peripheral portion of substantially lesser diameter than said first portion; said mandrel having a tapered expander enlarging in external diameter in a direction from said second portion to said first portion; initially retracted annular packing means of a ductile malleable material having a melting temperature above about 800 F. initially surrounding said second portion and having an initial internal diameter substantially less than said first portion; and means for relatively shifting said packing means longitudinally along said second portion over said expander onto said first portion and into firm sealing engagement with the conduit and first body portion.

12. In a well packer adapted to be set in a conduit disposed in a well bore: a body; a mandrel; means releasably securing said mandrel to said body; said body having a first generally cylindrical peripheral portion and an expander extending longitudinally from said portion; said mandrel having a second generally cylindrical peripheral portion of substantially lesser diameter than said first portion; initially retracted annular packing means of a ductile malleable material having a melting temperature above about 800 F. initially surrounding said second peripheral portion and having an initial internal diameter substantially less than said first portion; and means for relatively shifting said packing means longitudinally along said second portion over said expander onto said first por- 10 tion into firm sealing engagement with the conduit and first body portion.

13. In a well packer adapted to be set in a conduit disposed in a well bore: body means; an initially retracted soft aluminum sleeve adapted to surround said body means; expander means movable relatively longitudinally within said sleeve to enlarge its internal and external diameters and force it against the conduit; and means for shifting said sleeve and expander means simultaneously in opposite longitudinal directions to enlarge said sleeve.

14. In a well packer adapted to be set in a conduit disposed in a well bore: body means having a first generally cylindrical peripheral portion and a second gener ally cylindrical peripheral portion of substantially greater diameter than said first portion and also having a tapered expander between said portions; an initially retracted annular soft aluminum sleeve initially surrounding said first portion and having an initial internal diameter substantially less than said second portion; and means for relatively shifting said aluminum sleeve longitudinally along said first portion over said expander onto said second portion and into firm sealing engagement with the conduit and second body portion, the major portion of said sleeve being shifted onto said second portion.

15. In a well packer adapted to be set in a conduit disposed in a well bore: a body member; a mandrel member; means releasably securing said mandrel member to said body member; said body member having a first generally cylindrical peripheral portion; one of said members having a second generally cylindrical peripheral portion of substantially lesser diameter than said first portion; one of said members having a tapered expander between said portions; an initially retracted soft aluminum sleeve initially surounding said second peripheral portion and having an initial internal diameter substantially less than said first portion; and means for relatively shifting said aluminum sleeve longitudinally along said second portion over said expander onto said first portion and into firm sealing engagement with the conduit and first body portion.

16. In a well packer adapted to be set in a conduit disposed in a well bore: body means; an initially retracted soft aluminum sleeve adapted to surround said body means; expander means movable relatively longitudinally within said sleeve to enlarge its internal and external diameters and force it against the conduit; said aluminum sleeve having a plurality of longitudinally spaced external circumferential ribs; and means for shifting said sleeve and expander means simultaneously in opposite longitudinal directions to enlarge said sleeve.

17. In a well packer adapted 'to be set in a conduit disposed in a well bore: a body member; a mandrel member; means releasably securing said mandrel member to said body member; said body member having a first generally cylindrical peripheral portion; one of said members having a second generally cylindrical peripheral portion of substantially lesser diameter than said first portion; one of said members having a tapered expander between said portions; an initially retracted soft aluminum sleeve initially surrounding said second peripheral portion and having an initial internal diameter substantially less than said first portion; and means for relatively shifting said aluminum sleeve longitudinally along said second portion over said expander onto said first portion and into firm sealing engagement with the conduit and first body portion; said aluminum sleeve having a plurality of longitudinally spaced external circumferential ribs.

18. In a well packer adapted to be set in a conduit disposed in a well bore: body means; an initially retracted soft aluminum sleeve adapted to surround said body means; expander means movable relatively longitudinally within said sleeve to enlarge its internal and external diameters and force it against the conduit; said aluminum sleeve having a plurality of longitudinally spaced external circumferential ribs; and means for compressing 11 12 said enlarged sleeve against the conduit with a force eX- 1,915,771 6/1933 Wickersham et al. 166-192 X ceeding the yield strength of the soft aluminum sleeve, 1,974,172 9/ 1934 Branch 166-192 which force is less than the ultimate strength of said soft 2,214,226 9/1940 English 166-192 X aluminum sleeve. 2,656,891 10/1953 T oelke 166-63 5 3,155,164 11/1964 Keener 166-192 References Cited by the Examiner L. Primary Examiner. 1,336,738 4/1920 Fletcher 166-181 X CHARLES E OCONNELL, Examiner- 1,512,621 10/1924 Mack 166-192 X D. H. BROWN, Assistant Examiner.

1,686,185 10/1928 Spang 166-192 X 10 

13. IN A WELL PACKER ADAPTED TO BE SET IN A CONDUIT DISPOSED IN A WELL BORE: BODY MEANS; AN INITIALLY RETRACTED SOFT ALUMINUM SLEEVE ADAPTED TO SURROUND SAID BODY MEANS; EXPANDER MEANS MOVABLE RELATIVELY LONGITUDINALLY WITHIN SAID SLEEVE TO ENLARGE ITS INTERNAL AND EXTERNAL DIAMETERS AND FORCE IT AGAINST THE CONDUIT; AND 